Arc current controlling apparatus for welders&#39; helmets



Sept. 15, 1959 G. F. TOEBE ARC CURRENT CONTROLLING APPARATUS FOR WELDERSHELMETS Filed Sept. 18, 1958 INVENTOR GEORGE F. TOEBE ATTORNEYS UnitedStates Patent ()filice Patented Sept. 15, 1959 ARC CURRENT CONTROLLINGAPPARATUS FOR WELDERS HELMETS George F. Toebe, Chippewa Falls, Wis.Application September 18, 1958, Serial No. 761,877 1 Claim. (Cl.219-147) This invention appertains -to safety apparatus for welders, andmore particularly to va.novelmeans for automatically controlling theclosing movement of the dark glass of a welders helmet and are circuitupon the touching of the weld rod with the work, and isan improvementonthe Morrell patent (assigned to applicant) No. 2,778,928, issued January22, 1957.

One .of the primary objects of the present invention is to provide a newand novel means for actuating and controlling the main switch (employedfor releasing the dark glass to permit the same to move to an operativeposition and to .close the control switch), whereby to insure a positiveand desired operation thereof.

Another salient object .of the invention is to provide ,means for urgingthe main switch to a closed position and for holding the switch in such.position by .a spring, with a solenoid operated catch for releasing theswitch to permit the same tomove under the influence of the spring; anda solenoid operated means for returning the switch against the influenceof the spring to an openposition for .re-engagemcnt by the releasecatch, the arrangement being such as to eliminate the dashpot as.employed in the mentioned Morrell patent.

A further important object of my invention .is the provision of a noveland simplified form of circuits and solenoids to :bring about the,desired safety features for .the welder.

With these and other objects in view, the invention consistsin the novelconstruction, arrangement and formation of parts, as will be morespecifically described and claimed, and illustrated in the accompanyingdrawing, in which drawing the single figure is a diagrammatic viewshowing the wiring circuits and parts actuated by the opening andclosing thereof.

Referring to the drawing in .detail, the letter H generally indicatesthe helmet and .C the novel circuits used in conjunction with the helmet.and forming a .part of the invention.

The helmet His of the same type and character shown in the Morrellpatent, and in the present application the helmet has .only been showndiagrammatically. The helmet .isof the general type and character as isnow in common use and the same is in the nature of a shield held on thewelders head by pivoted head straps (not shown).

The helmet is provided with a visor 1 having slidably associatedtherewith a dark glass or shutter 2. The dark glass or shutter 2 ismounted for sliding movement toward and away from the visor and hassecured thereto a depending shank 3. The shank3 on one side is providedwith akeeper notch 4 and on the other side adjacent to its lower endwith a catch nose 5. A switch operating ear '6 is also formed on thelower end of this shank. A contractile coil spring 7 has its oppositeends secured respectively to the lower end of the shank 3 and to a rigidpart of the helmet and this spring functions to normally urge and holdthe dark glass or shutter 2 inaraised position in front of the welderseyes. Also slidably mounted onthe helmet is an operating rod 8 and thesame is provided with a hand grip 9 to facilitate the sliding .of therod up and down by the welder. The upper end of the rod 8 ,is providedwith a laterally projecting nose 10 for interengagement with the nose 5of the shank 3. A contractile coil spring 11, has its opposite endssecured respectively to the rod 8 and to ,a stationary part of thehelmet and this spring functions to normally hold the operating rod in araisedposition and above the nose 5. .It can be seen, however, that whenthe dark glass 2 and its shank 3 are .in a raised position that bypulling .downon the hand grip 9 and the rod 8, the nose 10 will engagethe nose 5 and hence draw the shank 3 and the .dark glass or shutter 2therewith.

.Mounted .for horizontal sliding movement on the helrnet is a latch bar1-2. For-med on or carried .by the ,innerend of the latch bar 12 is anarmature or plunger core 13 of a solenoid coil 14. vA spring 15 normallyurges the plunger 13 and the latch bar 12 toward the shank 3 ,and whenthe shank 3 and the dark glass 2 are ,in their lowered position thelatch bar 12 engages in the keeper .notch 4 and holds the shank and the.dark glass in their lowered positions against the tension of the spring7. When arcircuit ,isclosed through the solenoid coil 14, the .latch12.is retracted and theshank 3 and dark glass 2 are quickly moved to araised operative-position .by the spring 7.

Also carried by the helmet is a control switch 16 and the same includesspaced .upper and lower leaves ,17 and 18 and an intermediate resilient.leaf 19. All of the sleaves are formedfrom electricconducting material.The .upper leaf .17 is provided with a contact point 20, and the lowerleaf 18 is .provided with a similarcontact point 21. The intermediateresilient leaf 19 is provided with oppositely extending contact points22 and 23. The (normal resiliency of the leaf 19 holds .the contact 23in electrical engagement with thecontact 21 and the leaf 19 'is extendedto form a foot 24, which .is disposed in the .path'ofthe movement of theoperating ear 6. When the shank 3 is in its raised position, as shown indotted lines, the ear .6 engages the foot 24 and moves the leaf 19against its inherent resiliency to a raised position, moving the contact23 away from the contact 21 and moving the contact 22 in electricalengagement with the contact 20. All of the leaves are separated byblocks of insulation 25. The helmet carries a safetyswitch 26, which isof the type to break circuits when the straps-of the'helmet are moved toan inoperative position. Briefly, the switch includes a stationaryannular casing 27 and an axially disposed rotor 28 :rnovable with thestraps. The housing includes spaced contacts 29, 30 and 31. The rotor 28includes spaced contacts 32, 33 and 134. With the helmet in place andthe straps in their lowered position the contacts 32, 33 and 34 engagerespectively the contacts 29, 30 and 31. With the helmet straps in theirraised inoperative position, the mentioned contacts are moved away fromone another, but contact 33 is moved into electrical engagement with thecontact 31. The purpose of this safety switch and the arrangement of thecontacts will be later described. All of the parts mentioned are carriedby the helmet as suggested by the broken lines in the drawing.

in conjunction with the helmet and the parts just described, I utilizethe novel wiring circuits C which will now be set forth. Heavydutywelding lines 35 and 36 are provided which lead from any suitable sourceof electrical energy, or power, such as a generator 37 forming a part ofthe welding machine (not shown). As in the usual practice the wire 36 iselectrically connected with the work W. A branch main welding line orwire 38 is electrically connected with the holder 39 for the weld rod40. Operating in conjunction with the main welding circuit is a maincontrol switch 41 and this switch includes a stationary body section 42carrying spaced electrically insulated contacts 43 and 44. This mainswitch 41 includes a movable section 45 carrying spaced apart butelectrically connected contacts 46 and 47. The movable section 45 isoperated by the plunger 48 of a solenoid 49. A spring 50 normally urgesthe plunger and the movable section 45 of the switch toward thestationary section 41 when the solenoid is deenergized. With the movablesection 45 in engagement with the stationary section 41 contacts 46 and47 electrically engage contacts 43 and 44 and electrically unite thesame.

The main line 35 is electrically connected with contact 44 and contact43 is electrically connected to the wire 38 by a branch wire 51. So far,it can be seen that with the contacts 43 and 44 electrically connectedas just described, the main welding circuit is completed and currentflow is from generator 37, wire 35 through switch 41, wire 51, wire 38,weld rod 40, work W through wire 36, back to the generator 37. When thesolenoid 49 is energized the plunger 48 and the movable section 45 aredrawn back against the tension of the spring 50. The plunger and themovable switch section 45 are held in this position against the tensionof the spring 50 by a releasable catch 52. The catch 52 includes avertically movable block 53 carried by the plunger 54 of a solenoid 55.Pivoted to the block 53 is a pivoted latch lever 56. The lever is freeto swing in one direction and its movement is limited in the oppositedirection by a stop pin 57. With the movable section of the switch 45 inrear of the pivoted latch nose 56 the latch nose, due to its engagementwith the pin 57 holds the movable switch section 45 in its retractedposition against the tension of the spring 50. It can be seen that whenthe movable section 45 is in a circuit closed position and the solenoid49 is energized, then the switch section 45 moves away from thestationary section 41 and engages the latch lever 56 and rocks the sameon its pivot away from the pin 57 until the movable section 45 ridespast the latch lever. At this time, a light tension spring 58 moves thelatch lever back to its normal switch holding position. When thesolenoid 55 is energized, the block 53 and the latch nose 56 are bodilylifted out of the path of movement of the movable switch section 45. Aspring 59 is employed for normally holding the block 53 and the latchlever 56 is a lowered position when the solenoid is de-energized.

The opposite terminals of the solenoid 55 are electrically connectedrespectively with a wire 38 and a conductor wire 60 which leads tocontact 29 of the safety switch, which is in engagement with the contact32 (the helmet being in operative position). Contact 32 has electricallyconnected therewith a wire 61 electrically connected with one terminalof the solenoid coil 14 and the other terminal of this coil haselectrically connected thereto a wire 62 which leads to the contact 30of the rotatable switch. Contact 33 has electrically connected thereto areturn branch wire 63, which is electrically connected with wire 35. Afuse link 64 can be incorporated in the length of the wire 63 if suchshould be desired. With the weld rod 40 in engagement with the work Wcurrent flow is as follows: from the welder 37, through wire 36, work W,weld rod 40, wire 38 through coil 55, wire 60, through safety switch 26,wire 61, through coil 14, wire 62 and safety switch 26, through wire 63back to the generator. This energizes the solenoid 14 and the latch bar12 is moved away from the shank 53 against the tension of the spring 15.Spring 7 immediately moves the dark glass 2 to its raised operativeposition. At this moment, the circuit is not closed through the mainwelding circuit in view of the fact that switch 41 is in its openposition. Upward movement of the shank 3 operates the resilient leaf 19of the helmet switch 16, and consequently, contact point 22 electricallyengages contact point 24). It is to be noted that leaf 17 carryingcontact point 20 is electrically connected by a branch wire 65 with wire61 and that the intermediate resilient leaf 19 is electrically connectedto wire 62 by a branch wire 66. Consequently, coil 14 is now shuntedthrough wires 62, 66, leaf 19 and leaf 17, wire 65, and wire 61. At thistime, with the shunting of the coil 14, solenoid 55 is energized andcurrent flow is as follows: generator 37, wire 36, work W, weld rod 40,wire 38, through solenoid 55, wire 60, through safety switch 26, wire65, through leaves 17 and 19 of switch 16, through wire 66, through wire62, safety switch 26, through wire 63, wire 35 back to generator.

With the energizing of solenoid 55 catch block 53 is raised and thespring 50 will force the movable section 45 of main switch 41 to aclosed position. At this time, the main welding circuit is closed, andas stated heretofore, current flow is from generator 37 through wire 36,work W, weld rod 40, wire 38, wire 51, through section 41, through wire35 to the generator. The welding can now he proceeded with.

When the welding is completed, and the weld rod 40 is removed from thework W, the dark glass is pulled down by the operator by actuating theknob 9 and the dark glass will be held in this lowered position by thelatch 12. At this time, leaf switch 19 of the helmet switch 16 willreturn to its normal position and contacts 21 and 23 will be inengagement. The leaf 18 of the helmet switch 16 are electricallyconnected to contact 34 of the safety switch 26 by a wire 67 and contact31 of said switch is electrically connected to one terminal of thesolenoid 49 by a wire 68. The other terminal of the solenoid 49 isconnected by a branch wire 69 to the main line 36. At this time, it isto be noted that wire 69, for safety purposes, has interposed therein asafety switch 70 embodying a pivoted switch lever, which is in itsclosed position when the movable portion 45 of the main switch 41 is inits closed position with the stationary section 42. With the shutter ordark glass 2 in its lowered position and leaves 18 and 19 of helmetswitch 16 in circuit closed position, current flow is as follows:generator 37, wire 69, though solenoid 49, through wire 68, safetyswitch 26, wire 67, switch 16, wire 66, wire 62 through safety switch26, through wire 63 back to generator 37. With the energizing ofsolenoid 49 the switch 42 is opened and held in that position by thecatch 52 and the welding circuit is now broken.

When the welder moves the helmet and moves the helmet straps to aninoperative position, the contacts 32 and 29 are disconnected as are thecontacts 30 and 33. This insures the safety of the welder.

Hence, welding cannot continue until the helmet is again pulled down inwelding position.

From the foregoing description, it can be seen that I have provided animproved and simplified mechanism for protecting the welder.

Changes in details may be made without departing from the spirit or thescope of this invention, but what I claim as new is:

In combination with a welding helmet, a movable shutter and an arccircuit controlling apparatus, spring means normally moving the shutterinto a raised eye protecting position, a solenoid operated catch forholding the shutter in a lowered inoperative position against tension ofthe spring, an arc welding circuit including a welding electrode and theWork, a normally opened main switch in said arc welding circuit, springmeans normally holding the switch in a circuit closing position,solenoid operated means for moving the switch to an open position, acatch for holding the switch in an open position against the tension ofthe spring, solenoid operated means for moving the catch to a releasedposition, a branch circuit including the solenoid of the catch for theshutter energized upon the engagement of the weld rod with the worknormally in series with the solenoid of the release 5 6 catch for themain switch, means shunting the first menmain switch upon the lifting ofthe Weld rod from the tioned solenoid upon movement of the shutter to araised Work for opening said main switch. eye protecting position,whereby to bring about increased current flow through the solenoid forthe catch of the References Cited in the file of this Patent main switchand the energizing of said solenoid to per- 5 UNITED STATES PATENTS mitthe closing of the main switch under the influence of 2,778,928 M 0 IT611 Jam 22 1957 its spring, and means for energizing the solenoid of the

